1. Field of the Invention
The present invention relates to a temperature control device, and more particularly, pertains to an electronic temperature controller with a uniquely aligned control knob which also includes a detachable control relay module.
2. Description of the Prior Art
Prior art electronic controller designs have utilized methods which have rigidly mounted the control circuits, either enclosed or open-board, onto the mercury displacement relay (MDR) coils, coil brackets or the contact assemblies. These prior art methods have used screw fasteners in a multipoint arrangement to maintain mounting security. In general, the mounting geometries of these prior art designs have required that a multiple number of the same type of control circuits be packaged to permanently engage with the various coil forms and/or contact configurations in the MDR structure. Electrical connections between the prior art temperature controls and the relay coils have been by common wiring techniques. The prior art structures have often utilized some form of mounting screws for this purpose. Prior art time delay function modules utilized discrete wires routed between the control and the coil connections. These hard wire techniques did not provide for interchangability nor for easy replacement or servicing.
Methods commonly employed for mounting a control knob onto a potentiometer shaft generally utilized some form of a metal insert and/or a set screw. Prior art calibration orientation utilized a flattened shaft and flat mating surface in the control knob assembly.
The present invention overcomes the disadvantages of the prior art by providing a mechanical package which mounts an industrial control electronic system onto an MDR coil assembly.